DRESSTA TD-25M EXTRA, Service Manual

Page: 369 / 595

PUMPS
SECTION 10A
Page 3
DRESSTA TD-25M EXTRA
EQUIPMENT PUMP
Fig. 10A.3. Vane Pump Operation
1. Rotation
2. Inlet
3. Rotor Ring
4. Rotor
5. Outlet
6. Vane
7. Inlet 8. Shaft
9. Outlet
10. Insert
11. Rotation
12. Outlet
13. Inlet
14. Pressure to insert 15. Vane
16. Rotor
17. Direction of Rotation
18. Rotor Ring
19. Sharper Edges Lead Direction of Rotation
20. Pressure to Bottom of Vane
Rear Pumping Cartridge (Refer to Fig. 10A.7)
This pump is used to develop hydraulic oil for the operation of the pilot valve control system.
The positive pumping cartridge is the rotary vane type with shaft side loads hydraulically balanced.
The flow rate depends on the pump speed at which it is driven. The pump consists of a ported end
cover (39) and a pumping cartridge. Components of the pumping cartridge are an elliptical rotor
ring (43), a slotted rotor (41) splined to fit the drive shaft, twelve vanes (42) to fit the rotor slots,
a wear plate (48) and a pressure plate (46) with spring (45). The pumping cartridge is sandwiched
between the end cover (39) and the rear cover (2). A bushing pressed in the pressure plate
supports the drive shaft and centers the rotor within the cam ring. As the shaft is driven, the rotor
and vanes generate flow by carrying fluid around the elliptical rotor ring contour. Fluid enters
the cartridge via the inlet housing port through the porting in the housing walls through the porting
in cartridge B's outlet support plate (7) through the center of the rear cover and past the wear plate
and is discharged through the pressure plate into the end cover outlet port.